V3.4.8 will not install

Tried updating to latest version 3.4.8 and followed the prompts to uninstall/save xml/reboot. When i return to desktop and try to install RD tells me a previous version is installed. I followed Forum suggestion of removing .sys files and reg removal to which was futile.

Restored system (thank goodness i made a restore point) and RD returned with 3.4.7 version.
Then i saved xml again, reset temp files to system and unmounted drive. then Tried Revo Uninstaller Pro and removed the program as i saw the sys and registry entries on screen for deletion.
Rebooted.
Same annoying message about previous install found...
System restored and version 3.4.7 returns.
Please fix RD to become user (un nerving) friendly at upgrading. Having to uninstall and rebooting and all with no success is irritating.

Thank you. That was precisely the information (From earlier post--I followed Forum suggestion of removing .sys files and reg removal to which was futile.)
After Windows Uninstall....I checked the 'suggestion'- Sys files/Reg Entries and program location and those attributes were not to be found so i rebooted and lo and behold afterwards the same message.[repeating first post.]
RD would not install.

Last night i saved XML file, changed temp file location/ unmounted disk, and then uninstalled program. rebooted. check the 'suggestion' , as no program folder existed, registry keys not located, and sys files not found.

Thank you. I see and understand but none of that changes the fact that having verified the registry and folder with the mentioned entries and files are in fact gone. the 3.4.8 installer will not move past that point.

Finally! I was able to clean out RD by starting with Registry, except i did not find the vvramd entry, and then returned the temp folder to the system folder and then exited the program. The system32 files were locked so i rebooted and then removed them and then rebooted and RD installer then loaded.